Generator Motor
The generator motor is a 3-phase permanent magnet AC motor connected to the sun gear of the planetary gear set. The generator power inverter (internal to the transaxle) receives a DC current from the high voltage traction battery. The DC current is inverted to an AC current, which is controlled by the TCM and the generator control unit (GCU). Depending on the mode of operation, the generator motor can rotate in the same (clockwise) or reverse (counter clockwise) direction as the internal combustion engine. The TCM also monitors generator position, speed, phase current, power inverter temperature, coil temperature, and voltage. It processes a variety of PCM and traction battery control module (TBCM) inputs to determine generator function. The inputs are divided into 2 categories: the hardwired signals and the network messages. The inputs used to determine generator function include the total torque desired, the engine speed desired, the generator mode, the generator shutdown, and the vehicle mode. The generator operates in one of the following generator modes: torque, speed, engine cold start, engine normal start, engine high speed start, and engine enhanced speed control stop. The generator is used as a starter for the internal combustion engine, charges high voltage traction battery, and controls engine speed. The TCM reports the generator error status to the PCM. The PCM initiates an appropriate limited operating strategy (LOS) mode and sets the diagnostic trouble code (DTC) P1A0D (Hybrid powertrain control module - generator disabled) based on the error status it received. The TCM also sets a DTC which indicates why the generator motor failed.